Developments of the Glen Lyon FPSO Digital Twin: Vessel Response and Structural Monitoring

Abstract This paper presents the continuing developments of the Glen Lyon FPSO Digital Twin. The objective of the Glen Lyon Digital Twin has always been to monitor and inform structural barrier health and verify operation within the allowable design limits. A detailed vessel motion response and loads monitoring is being undertaken to keep track of the fatigue life consumption of the hull structure, and to take mitigating actions as needed to maintain integrity. The structural response monitoring system onboard is contained within the vessel’s Integrated Marine Monitoring System (IMMS), which consists of various sensors, including accelerometers and strain gauges. The measurements from these are accessed and post-processed through BMT DEEP, harnessing the benefits of Digital Twin Technology, by bringing in data from all sources and enabling to synthesize and monitor the FPSO response in near real-time from any remote location. The structural dashboard monitors the vessel dynamic stability, relative environment headings, and vessel offsets, through several statistical distribution charts. The hull girder bending moments are continuously monitored through deflections measured by the deck strain gauges. Also, the vessel fatigue damage is computed from the deck strain gauge measurements. Apart from these, the vessel motion responses like relative wave elevations and vertical accelerations at the turret center, are being utilized to help monitor vessel fatigue life consumption by comparison with established fatigue curves using these parameters. Comparisons are made with the predicted fatigue damage rates during the vessel design. Some key insights and findings from these comparisons are presented. The challenges faced in this process are highlighted, along with the steps taken to overcome those.